This invention relates to a device such as a semiconductor device having a refresh function, and a control method thereof.
A semiconductor device including a volatile memory, element is required to perform a refresh operation periodically to maintain information held in the volatile memory element. Such periodical operation may be utilized to trigger another operation.
For example, US2007/0148796A1, or JP2007-123987A (Patent Document 1) discloses a technique in which an impedance adjustment (ZQ calibration) at an external terminal is carried out together with a refresh operation in synchronization with a refresh cycle.
JP2005-292947A (Patent Document 2) discloses a technique in which variable delay data from a DLL (Delay-Locked Loop) is updated together with a refresh operation in synchronization with the refresh operation.